Fascinating distinct reactivity of 3- or 2-aminopyridines with carbon nanotubes

Reductive electrografting of in situ produced diazopyridinium cations: Tailoring the interface between carbon electrodes and electroactive bacterial films

“…cations has been mostly carried out with 3-diazopyridinium cations, [19][20][21][22][23] because 4-aminoand even more 2-amino-diazopyridinium salts are considered highly unstable and claimed not to be useful for surface functionalization. [22], [21] However, some works report the grafting from 4-amino precursors. [24,25] In this work, we report the electrografting of in situ produced diazopyridinium cations using 2-, 3-and 4-aminopyridine (Scheme 1) in order to functionalize the carbon surface with pyridine units.…”

One-dimensional nitrogen-containing carbon nanostructures

“…The formation of cyclic benzyl carbamate and pyrrolidine functional groups on MWNCNTs surfaces was evidenced by XPS. A rapid and simple, room temperature preparation of new kinds of water-, alcohol-or tetrahydrofuran-dispersible SWNCNTs, by the reaction of SWCNTs with a diazonium salt of 3-aminopyridine, has recently been reported [305]. The functionalization of pristine SWCNTs to SWNCNTs by diazoniumbased method with five-membered N-containing heteroaromatic amines (2-aminoimidazole sulfate, or 3-aminopyrazole) [306], or with benzoic acid moiety by using 4-carboxybenzene diazonium tetrafluoroborate [307], has successfully been performed.…”

Modification of Glassy Carbon Electrode by Electrografting of In Situ Generated 3-diazopyridinium Cations

“…carbon, [8][9][10][11][12] metal, 5,[13][14][15][16][17][18] and semiconductor [19][20][21][22][23] ) and in different media (eg. water, [24][25][26][27] organic, [28][29][30][31][32] and ionic liquids [33][34][35] ). Several substituted phenyl groups have been grafted on carbon 24,28,[30][31][32]36,37 or gold electrodes.…”

“…15,16 However, the number of studies dealing with the formation of diazopyridinium cations and their stability for the electrochemical or chemical modification of an electrode surface are more limited. [25][26][27]38,39 Interestingly, modified electrodes with pyridine groups and other nitrogen-based heterocycles, allow further chemical modification on the attached groups, 25,40 complexation of metallic ions 39,[41][42][43][44][45] and could be used to develop electrocatalytic sites. 42,[45][46][47] Pyridine has been chemically grafted on single walled carbon nanotubes (SWNTs) by reaction with 4-diazopyridinium cations generated in-situ and the resulting pyridine-functionalized SWNTs have been shown to act as a gelator to form hydrogels of poly(acrylic acid).…”

“…25 The reactivity of 3-aminopyridine, 2-aminopyridine and 2-amino-3-methylpyridine in a diazonium-based functionalization with SWCNTs has been investigated and it has been found that only 3-aminopyridine was successful grafted to yield functionalized SWCNTs. 27 Alternately, pyridine has been recently electrografted on glassy carbon using the diazonium modification method with 3aminopyridine in acetonitrile at 0 • C. 39 The surface concentration of the pyridine groups and the barrier properties of the modified glassy carbon electrodes in the presence of redox probes were determined before and after complexation with ruthenium metal cations. Recently, we reported the modification of glassy carbon by electrochemical reduction of in-situ generated 3-diazopyridinium cations in acid media at room temperature.…”